This week's tip of the day by Gavin Goulden uses Shadowbox within ZBrush to quickly and easily create models

Sometimes, when creating a character or sculpting within ZBrush, you are 'in the zone' and what can kill that momentum is bouncing back and forth from a 3D application to ZBrush. In this tutorial, I will show you an easy way to quickly prototype objects that can be used as a base for further sculpting, or simply used in addition to your sculpt. The Shadowbox tool acts much like a 3D printing machine, where you have a block of material that gets carved away based on the masks you draw. While not producing clean results, these models can be used as smaller details where clean topology isn't always needed, or used as a guide to model over. This method can also allow you to follow blueprints to model things rapidly, and use these models in future projects.

Shadowbox is a great way to model objects quickly without needing to bounce back to a 3D modeling program

Prototyping Models with Shadowbox

To begin, navigate to Geometry > Shadowbox within ZBrush. This will display an isometric cube with 3 planes showing. This serves as the bounding box for your model; by default Shadowbox is creating a cube that you can then carve away at to get the model that you would like. You are essentially telling ZBrush what information to generate by drawing masks on any of these planes. Drawing a mask on one side will create information the entire way through until you exclude information on another plane by masking it out. Once you are happy with your model, you can simply click Shadowbox again and your new base mesh is ready to continue sculpting and to make further edits. As a note, re-entering Shadowbox will distort some information as ZBrush will recalculate the model Shadowbox creates, so, if you had finer details and do not want to lose them, you should duplicate your model to be safe.

Carve out information by using masks which serve as the 'shadow', or outline, of your model

Top tip 1: Shadowbox Resolution

If you notice that the information within your Shadowbox is pixilated, there's a good chance that you need to work at a higher resolution. Low resolution information can cause your final model to become messy as the mask information, which dictates the final model, will be drawing each pixel rather than smooth curves. Before jumping into Shadowbox, increase your resolution in the Remesh section to something higher than the default 128.

Increase your resolution for smoother results in Shadowbox. If you only need to create a rough model that you will then subdivide and sculpt normally, keep the default or decrease it for a lighter base mesh

Top tip 2: Using Alphas in Shadowbox

Sometimes you have a specific idea in mind for what your final design will be, and it could be easier to draw this out in Photoshop. Things like a gear, jewelry, mechanical elements, and so on, can be created as an Alpha and quickly applied to Shadowbox. Simply load in an Alpha that you have created and, with the DragRect brush, draw your Alpha as a mask. Much like the freehand information you would normally draw, this creates a model exactly to the proportions you created in your Alpha texture.

Use pre-made Alphas for accurate information in Shadowbox when you have a specific design in mind